Gas turbine engines generally include a compressor to pressurize inflowing air, a combustor to burn a fuel in the presence of the pressurized air, and a turbine to extract energy from the resulting combustion gases. The turbine may include multiple rotatable turbine blade arrays separated by multiple stationary vane arrays. A turbine blade array may be disposed radially inward of an annular blade outer air seal (BOAS). Minimal blade tip clearance between turbine blades and a BOAS is associated with maximum efficiency. Due to thermal expansion and centrifugal force, clearance between the turbine blade array and the BOAS may be large.